Sheet transporting unit for use in printing machines or the like

ABSTRACT

A printing apparatus wherein imprinted sheets are provided with cuts surrounding selected areas of the sheets and wherein the cutouts corresponding to such selected areas are thereupon bodily separated from the remnants of the respective sheets during travel between two rotary drums has a sheet transporting unit wherein two endless chains entrain a succession of sheet gripping devices so that the gripping devices engage successive sheets at a station located upstream of the drums and deposit the remnants of sheets downstream of the drums. The gripping devices are normally guided by rails which define therefor an endless path. A portion of each chain and portions of the rails can be pivoted between an operative position in which the endless path is completed and an inoperative position in which the endless path is interrupted. The pivoting takes place about an axis which is parallel with and adjacent to the axis of one of the drums, and such drum moves sideways and away from the other drum in response to pivoting of the movable portions of rails so as to afford access to the space between the drums. The system for moving the portions of rails employs a worm drive having a fixedly mounted worm wheel, a worm which meshes with the worm wheel and is secured to a frame for movable portions of the rails, and a reversible motor which can rotate the worm wheel in two directions.

United States Patent [1 Nitzsehe et al.

[ 1 May 6,1975

[ SHEET TRANSPORTING UNIT FOR USE IN PRINTING MACHINES OR THE LIKE [73 I Assignee: Veb Polygraph Leipzig Kombinatfiir Polygraphische Maschinen und Ausrustungen, Leipzig, Germany [22] Filed: Aug. 14, I973 [21] Appl. No: 388,233

[52] US. Cl 225/96; 93/36 A [51 1 Int. Cl B26f 3/00 [58] Field of Search 225/94, 96, 100; 83/304,

[56] References Cited UNITED STATES PATENTS 2,686,673 8/1952 Morganuw......................... 271/200 2,814,343 11/1957 Anderson 83/157 2,843,061 7/1958 Bonebrakcr 225/100 3,497,120 2/1970 Fischer et al. 225/100 X Primary Examiner-Andrew R. .Iuhasz Assistant Examiner-Leon Gilden Attorney, Agent, or FirmMichael S. Striker [57] ABSTRACT A printing apparatus wherein imprinted sheets are provided with cuts surrounding selected areas of the sheets and wherein the cutouts corresponding to such selected areas are thereupon bodily separated from the remnants of the respective sheets during travel between two rotary drums has a sheet transporting unit wherein two endless chains entrain a succession of sheet gripping devices so that the gripping devices engage successive sheets at a station located upstream of the drums and deposit the remnants of sheets downstream of the drums. The gripping devices are normally guided by rails which define therefor an endless path. A portion of each chain and portions of the rails can be pivoted between an operative position in which the endless path is completed and an inoperative position in which the endless path is interrupted. The pivoting takes place about an axis which is parallel with and adjacent to the axis of one of the drums, and such drum moves sideways and away from the other drum in response to pivoting of the movable portions of rails so as to afford access to the space between the drums. The system for moving the portions of rails employs a worm drive having a fixedly mounted worm wheel, a worm which meshes with the worm wheel and is secured to a frame for movable portions of the rails, and a reversible motor which can rotate the worm wheel in two directions.

19 Claims, 9 Drawing Figures PATENTEBHAY 61% 3,881,646

sum 3 or 7 PATENTEDHAY ems 3.881.646

snm nor 7 PATENTEUHAY BIQYS 3.881.646

SHEET 50F T FEENTEE MAY 6 i975 SHEEI 8 BF 7 FIG? PATENTEBMAY ems 3881.646

SHEET m 7 SHEET TRANSPORTING UNIT FOR USE IN PRINTING MACHINES OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to printing and other sheet manipulating machines in general, and more particularly to improvements in apparatus for transporting sheets, especially imprinted sheets, between certain processing stations of printing or like machines. Still more particularly, the invention relates to improvements in apparatus which can be used to transport sheets in so-called rotary printing machines of the type wherein successive imprinted sheets are advanced first through a stamping or punching station, wherein the sheets are severed or grooved or perforated, and thereupon through a breaking-out or cutout-removing station wherein the portions surrounded by the cuts formed at the stamping station are removed from the respective sheets.

As a rule, the sheets which advance toward or reach the stamping station are engaged and advanced by gripping devices in the form of tongs or the like which normally engage the leading edges of sheets and form part of a conveying or transporting unit which moves successive sheets through and beyond the removing station and on to a stacking station where the sheets are assembled in the form of a pile or stack. The stamping station comprises a die or stamp in the form of a roll which cooperates with a counterroll to at least partially separate from successive sheets those portions or cutouts which are to be fully segregated from the respective sheets at the removing station. The removing station normally comprises a first removing drum which cooperates with a second or complementary removing drum for effective and reliable expulsion of cutouts from the remaining portions of successive sheets. The sheets advance first through the nip of the stamping rolls and thereupon through the nip of the removing drums to ultimately reach the stacking station. In order to insure accurate positioning of sheets relative to the stamping rolls and/or removing drums, the aforementioned gripping devices are connected to one or more endless flexible elements in the form of chains or the like and the chains are guided in stationary ways so that the gripping devices invariably advance along a predetermined path and can release the sheets when such sheets assume predetermined positions for accurate stacking on top of each other.

It is normally desirable to advance the sheets between the stamping and removing stations along a straight or slightly inclined path to thus prevent premature separation of cutouts from the remaining portions of sheets. It will be readily appreciated that excessive flexing of sheets immediately behind the stamping station could result in complete separation of cutouts upstream of the removing station whereby the cutouts could not be collected for disposal or for a given use. Moreover, the prematurely separated cutouts could contaminate the machine or even cause a stoppage and/or damage to or destruction of parts.

German Offenlegungsschrift No. 1,930,317 discloses a printing machine wherein the transporting unit advances successive sheets along a straight horizontal path extending between one or more pairs of printing rolls and on to a stacking station. The transporting unit comprises a series of gripping devices which remove blank sheets from a pile at the inlet of the machine and advance the sheets between the rolls of one or more pairs of printing rollers prior to depositing imprinted sheets at or close to the outlet end of the machine. The ways for the chain or chains which support and advance the gripping devices are fixedly mounted in the frame of the printing machine so that at least one roller of each pair of printing rollers between which the straight path for the sheets extends is not readily accessible for the purpose of inspection, cleaning, repair and/or replacement. For example, if one printing roller of each pair of rollers is located above and the other roller below the path of sheets, the other roller is not easily accessible even if the one roller is lifted or otherwise moved out of the way. This presents serious problems during the making of changes in setup, replace ment of printing plates and/or other operations.

The just described transporting units are also utilized for transport of sheets through the stamping and removing stations of conventional machines wherein imprinted sheets are moved between stamping rolls and removing drums. The problems in connection with such transporting units are the same as those in machines wherein the transporting unit with rigidly mounted ways for the gripping devices advances sheets between one or more pairs of printing rollers.

It was further proposed to install in printing or like machines sheet transporting units which are movable (either in their entirety or in part) between operative and inoperative positions. When moved to its inopera tive position, the transporting unit (or the movable part thereof) affords access to certain hard-to-reach components. Reference may be had to German Pat. Nos. 513,030, 703,284, 802,574 and l,267,228. As a rule, the sheet transporting unit is movable to an inoperative position to afford access to the ink fountain and type board of a flat bed machine. The just described trans porting units exhibit the drawback that their sheet gripping devices are not guided by fixed ways when the devices advance sheets between and beyond two or more stations so that the retention of sheets in a predetermined optimum path is not as predictable as necessary and that the sheets do not invariably assume optimum positions during travel through or during dwell at the processing stations. Therefore, the conventional transporting units which are movable between operative and inoperative positions are used mainly for the transport of sheets along relatively short and straight paths (which reduces the danger of misalignment of sheets due to the absence of fixed guide means for the gripping devices) or for transport of sheets from the last processing station to storage where a high accuracy in positioning of successive sheets is of lesser importance.

Furthermore, the heretofore known sheet transporting units which are movable between operative and inoperative positions must be displaced by hand. This imposes severe limits on the dimensions, complexity, accuracy and reliability of such transporting units.

SUMMARY OF THE INVENTION An object of the invention is to provide a novel and improved sheet transporting unit which is especially suited for use as a means for advancing sheets from a stamping to and beyond a removing station in a machine wherein successive imprinted sheets are treated for the purpose of removing therefrom one or more cutouts of any desired configuration and/or size.

Another object of the invention is to provide a sheet transporting unit which affords convenient access to adjoining parts of the machine to thus reduce the periods of idleness, to facilitate the work of attendants during changes in setup, during repair and/or during cleaning of such parts, and which is not only rugged and reliable but also safe so that its supervision can be entrusted to semiskilled or unskilled persons.

A further object of the invention is to provide a sheet transporting unit which can be installed in existing printing or analogous machines as a superior substitute for conventional sheet transporting units and which can transport large, smaller, shorter, or longer sheets with the same degree of accuracy and reproducibility as those conventional transporting units wherein the gripping devices for sheets are confined to movement along fixed paths by rigidly mounted ways which do not allow for movement of transporting units between operative and inoperative positions.

The invention resides in a combination of parts which can be utilized in a machine for providing imprinted sheets with cutouts and for separating the cutouts from the remnants of the respective sheets. The combination comprises a rotary sheet treating member (such as a drum which cooperates with a complementary drumshaped sheet treating member to bodily remove the cutouts from the remnants of successive sheets) and a sheet transporting unit which includes at least one chain or an analogous endless flexible element, sheet gripping devices connected with the flexible element, and guide means for the gripping devices and/or flexible element. The guide means comprises first portions (e.g. elongated rails) which are preferably secured to a stationary first frame and movable second portions which are preferably fixed to a movable second frame. The combination further comprisesdrive means which is actuatable to move a portion of the flexible element and the second portions of the guide means about a pivot axis which coincides with or is closely adjacent to the axis of the sheet treating member between an operative position in which the first and second portions of the guide means define for the gripping devices an endless path and an inoperative position in which the path is interrupted. The endless path preferably extends between the two rotary sheet treating members.

The gripping devices can receive sheets at a station which is located upstream of the sheet treating members, as considered in the direction of movement of the flexible element, and deliver remnants of sheets to sheet storing means located downstream of the sheet treating members.

The arrangement is preferably such that one of the sheet treating members moves sideways and away from the other sheet treating member in response to movement of the second portions of the guide means to the inoperative position. This enables an attendant to gain access to both sheet treating members and/or to the space in the general area of the sheet treating members.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved sheet transporting unit itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a diagrammatic side elevational view of a machine which embodies the improved sheet transporting unit, the movable section of the sheet transporting unit being shown in the operative position;

FIG. 2 is an enlarged partly elevational and partly vertical sectional view of the drive means for moving the movable section of the sheet transporting unit between the operative and inoperative positions;

FIG. 3 is a horizontal sectional view as seen in the direction of arrows from the line CC of FIG. 1;

FIG. 4 is an enlarged view of the locking mechanism for the movable section of the sheet transporting unit, substantially as seen in the direction of arrow A shown in FIG. 1',

FIG. 5 is an enlarged elevational view of a detail of the sheet transporting unit, with the movable section again shown in the operative position;

FIG. 6 is a view somewhat similar to that of FIG. 5 but showing the movable section of the sheet transporting unit in the inoperative position;

FIG. 7 is a plan view of a detail of the ways for the sheet gripping devices, substantially as seen in the direction of arrow AA in FIG. 5;

FIG. 8 illustrates on a larger scale the structure within the phantom line circle X of FIG. 5; and

FIG. 9 is a sectional view as seen in the direction of arrows from the line BB of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, there is shown an apparatus which is assumed to form part of or to constitute an attachment to a printing machine serving to imprint each of a series of successive paper sheets 1 with information in the form of typed text, pictures or the like. The imprinted sheets 1 leave the printing station by way of a chute 2 and advance by gravity toward the periphery of a drum-shaped transfer conveyor 3. The latter is assumed to attract successive sheets 1 by suction and to advance the sheets onto a stamping roll 5 cooperating with a complementary roll 4 to provide each sheet with incisions or weakened portions along which the material of the sheet can break to allow for separation of one or more cutouts (not specifically shown). The thus incised or weakened sheets 1 are taken over by a transporting unit 6 which is constructed and assembled in accordance with the present invention and includes gripping devices 13 serving to engage the leading edges of the respective sheets 1' during transport toward, between and beyond two sheet-treating drums 7 and 8 of a removing unit which fully separates the cutouts from the respective sheets 1. The remaining portions or remnants 1" of the sheets 1' advance beyond the sheettreating drums 7, 8 and are deposited on the top of each other to form a stack 9 on a storing platform which is preferably movable up and down as indicated by the arrow 9b. The path along which the sheets I and remnants l advance from the nip of the stamping rolls 4, 5 to a level above the storing platform 9a includes two straight outer portions and a slightly arcuate median portion (the latter extends through the nip of the drums 7, 8).

The present invention resides mainly in the transporting unit 6, in the removing unit including the drums 7, 8, and in the provision of means for moving a first section 62 of the transporting unit 6 relative to a fixedly mounted second section 61. The section 62 is movable between an operative position shown in FIGS. 1, 2, 5 and an inoperative position shown in FIG. 6. When it assumes the inoperative position of FIG. 6, the section 62 of the transporting unit 6 affords convenient access to a portion of or to the entire drum 7 as well as to the drum 8 to thus allow for inspection, removal of cutouts, repair, cleaning and/or other operations.

The transporting unit 6 comprises two endless flexible elements in the form of link chains 12 (see particularly FIGS. 2, 3 and 9) which are trained over pairs of sprocket wheels 10 and 11. The sprocket wheels 11 form part of the fixedly mounted section 6], i.e., their axes of rotation are stationary. The sprocket wheels 10 form part of the movable section 62 and are movable between a lower level shown in FIG. 1 (operative position of the section 62) and a higher level shown in FIG. 6 (inoperative position of the section 62). During movement between the two levels, the common axis of the sprocket wheels 10 travels along an are having its center of curvature 0 located close to the axis of rotation of the drum 7 (see FIG. 2). When the sprocket wheels 10 assume the positions of FIG. 1, they cause the chains 12 to advance successive gripping devices 13 close to those sheets 1' which emerge from the nip of the stamping rolls 4, 5 so that such gripping devices can engage and entrain the leading edges of the adjacent sheets 1' for transport toward and through the nip of the drums 7, 8. The sprocket wheels 11 are located above the stack 9 of remnants 1" on the platform 90.

The gripping devices 13 are connected to and extend transversely between the chains 12 of the transporting unit 6 (see HQ 3). Each gripping device 13 comprises followers (not specifically shown) which travel in channels defined by stationary guide means or ways 14 provided in the housing of the apparatus adjacent to the path of each chain 12. The construction of the ways 14 for the gripping devices 13 also forms part of the present invention. It is clear that, instead of or in addition to guiding the sheet gripping devices 13, the ways 14 can be designed to guide the link chains 12. The chains and/or the gripping devices can be provided with followers in the form of rollers which travel between rails forming part of the ways 14.

The chains 12 of the transporting unit 6 receive motion from the drum 7 in a manner as illustrated in FIG. 9. The common shaft for the sprocket wheels 11 (only one shown in FIG. 9) is shown at 49. A stationary frame 17 of the housing contains antifriction bearings 49a for the shaft 49 and is partially hollow so that it constitutes a gear case which is filled with a suitable lubricant. That end portion of the shaft 49 which is shown in FIG. 9 extends into a sleeve 50 which is mounted in the frame 17 and has a cylindrical extension 50a for a sprocket wheel 47 which is driven by the drum 7 by way of a link chain 46. The sprocket wheel 47 is freely rotatable on the extension 50a and constitutes one element of a mechanical claw clutch the other element of which is a clutch disk 51 secured to the shaft 49 by a key 52 so that it can move axially between an engaged position (shown by solid lines) in which the chain 46 drives the sprocket Wheels 11 by way of the clutch 47, 51, key 52 and shaft 49, and a disengaged position (shown by phantom lines) in which the sprocket wheel 47 is free to rotate with respect to the shaft 49. The means for moving the clutch disk 51 axially comprises a shifter fork 53 having a bifurcated portion extending into a circumferential groove 51a of the disk 51. The shifter fork 53 can be actuated by hand or by remote control in a manner not forming part of the invention. It suffices to say that the shifter fork 53 is to be actuated so as to disengage the clutch 47, 51 before the section 62 of the transporting unit 6 is caused to leave the operative position of FIG. 1.

The frame 17 further receives a braking device 153 which can engage the clutch disk 51 in the disengaged position of this disk so as to immediately arrest the sprocket wheels 11. The braking device 153 may comprise a portion which enters the groove 51a as soon as the disk 51 becomes disengaged from the sprocket wheel 47.

The section 62 of the sheet transporting unit 6 will be moved to the inoperative position of FIG. 6 whenever an attendant wishes to gain access to the stamping roll 5, to the space between the stamping roll 5 and the drums 7, 8 of the removing unit, and/or to the removing unit (especially to the drum 8). The movement of the section 62 to its inoperative position takes place simul taneously with movement of a first group of rails of the ways 14 relative to a second group of rails and with upward displacement of those portions of link chains 12 which extend to the left of the drum 7, as viewed in FIG. 1. When an attendant performs work on or in the region of the removing unit, it is customary to turn the drum 7 and/or 8 in order to facilitate cleaning, inspection and/or a change of setup. Such turning of the drum 7 and/or 8 should not result in movement of sheet gripping devices 13 between these drums because the gripping devices could injure the attendant and/or interfere with his work. Therefore, the attendant disengages the clutch 51, 47 by way of the shifter fork 53 not later than when the section 62 of the transporting unit 6 reaches the inoperative position of FIG. 6. The sprocket wheels 10, 11 are preferably arrested in predetermined angular positions in which the space between the drums 7 and 8 is free of gripping devices 13. This can be achieved by mounting the braking device 153 in such a way that it arrests the disk 51 in an angular position in which no gripping device 13 is located close to the drums 7 and 8.

When the section 62 is moved to the inoperative positon of FIG. 6, the chains 12 are tensioned by rollers 35 which are mounted in a pivotable frame 19 for the section 62 and by segments 36 which are mounted in the frame 19 close to the drum 7. The rollers 35 are secured to the frame 19 by fasteners 38 and cooperate with tensioning rollers 55 on the frame 17. The tension ing rollers 55 further cooperate with the sprocket wheels 10, 11 by engaging and tensioning the chains 12 when the section 62 reassumes its operative position. The drive means for moving the section 62 between its operative and inoperative positions is shown in FIG. 2. This drive means comprises a worm wheel 15 which is fixedly mounted in the stationary frame 17 and meshes with a worm 16 which is mounted on a worm shaft 16a. The worm 16 is installed in a casing 18 which is secured to the pivotable frame 19. The shaft 16a can be driven by a prime mover 20 (e.g., a reversible electric motor) by way of a clutch 21. That end portion of the shaft 16a which is remote from the clutch 21 abuts against a helical spring 22 which reacts against the casing 18. The worm assembly including the worm wheel 15 and worm 16 is of the self-locking type. The two halves of the pivotable frame 19 for the section 62 are connected to each other by one or more transversely extending beams 56 (see FIG. 3).

The operation of the drive means for the section 62 of the sheet transporting unit 6 is as follows:

When the motor 20 is started in a direction to pivot the section 62 from the operative position of FIG. 1, the worm 16 is rotated by the clutch 21 and travels clockwise, as viewed in FIG. 2, because it meshes with the worm wheel which is fixed to the stationary frame 17. The worm l6 and the shaft 16a are one part. The worm 16 is always in mesh with the worm wheel 15. As the worm 16 rotates with the shaft 16a, it moves axially upwardly and reaches a stop shoulder 181 of the casing 18. Since the casing 18 is rigid with the pivotable frame 19, the frame 19 thereupon begins to pivot about the center of curvature O and moves the section 62 to the inoperative position of FIG. 6. The motor is automatically arrested by a limit switch 48 on the frame 17 as soon as the frame 19 reaches the angular position of FIG. 6. The worm 16 continues to abut against the stop shoulder 181 of the casing 18 under the action of the spring 22 which is installed in prestressed condition.

In order to return the section 62 to the operative position of FIG. 1, the motor 20 is started in the opposite direction. The shaft 16a drives the worm 16 whereby the latter remains in mesh with the worm wheel 15 and travels in a counterclockwise direction, as viewed in FIG. 6. The prestressed spring 22 maintains the worm 16 in engagement with the stop shoulder 181 because the movement of rotation due to prestressing of the spring 22 (force acting against the stop shoulder 181 multiplied by the distance of the axis of the worm 16 from the center of curvature O) exceeds the moment of friction of a bearing sleeve for the shaft of the drum 7. The bearing sleeve 30 is in frictional engagement with the stationary frame 17.

The spring 22 reacts against an internal surface 182 of the casing 18. The counterclockwise movement of the casing 18 and frame 19 is caused by the spring 22 (which engages the surface 182) while the motor 20 drives the worm 16 in a direction to return the section 62 to the operative position of FIG. 1. The stress upon the spring 22 decreases to a minimum value when the moment of rotation of the section 62 (caused by gravity) equals the moment of friction of the bearing sleeve 30. The stop shoulder 181 then simply rests on the worm 16 while the latter travels counterclockwise back toward the position of FIG. 1. It will be seen that the shoulder 181 engages the worm 16 during the entire interval of lowering of section 62 to its operative position. The spring 22 insures that the movements of the section 62 with the frame 19 are practically free of shocks.

If the motor 20 fails to rotate the worm shaft 160 in an intermediate position of the worm 16 relative to the worm wheel 15, the self-locking action between the parts 15, 16 prevents any movement of the section 62 toward the operative position of FIG. 1. This reduces the likelihood of injury to attendants and/or damage to the transporting unit 6, drums 7, 8 and/or other parts of the apparatus wherein the transporting unit is put to use.

The electric motor 20 is arrested when the section 62 reaches its operative position. Such position is determined by a projection 23 provided on the pivotable frame 19 and then engaging a fixed abutment 24 (FIG. 1) on a frame 36 for the rolls 4, 5. The abutment 24 may constitute an electric switch in circuit with the motor 20 and the projection 23 may constitute a trip which opens the switch 24 as soon as the section 62 returns to its operative position. The shaft continues to rotate for a while whereby the worm 16 moves away from the stop shoulder 181 and stresses the spring 22. The extent to which the spring 22 is shortened is shown in FIG. 2, as at 12. Such shortening of the spring 22 insures that the frame 19 can reach the position of FIG. 1 without an appreciable shock. The starting or neutral position of the worm 16 is shown in FIG. 2.

When the motor 20 is again started in a direction to move the section 62 to the inoperative position of FIG. 6, actual pivoting of the frame 19 relative to the frame 17 begins only after the worm 16 reaches the stop shoulder 181. The limit switch 48 of FIG. 1 is engaged by a trip of the pivotable frame 19 to arrest the motor 20 when the section 62 reaches its inoperative position.

Referring to FIG. 4, there is shown a locking mechanism which serves to releasably hold the section 62 of the sheet transporting unit 6 in the operative position. The movable frame 19 is then coupled to the stationary frame 37 for the stamping rolls 4, 5. When the trip 23 of the frame 19 rests on the abutment or switch 24, the locking element or armature 26 of an electromagnet 28 on the frame 37 assumes the solid-line position I of FIG. 4 and engages a locking element or projection 25 of the frame 19 whereby the section 62 is held against pivotal movement from the operative position. When the electromagnet 28 is deenergized, a spring 27 urges the armature 26 against the frame 19. On energization of the electromagnet 28, the armature 26 pivots counterclockwise, as viewed in FIG. 4, to a phantom-line position II and becomes disengaged from the projection 25. Also, the armature 26 actuates a switch 29 which starts the motor 20 so that the drive means including the worm assembly 15, 16 begins to move the section 62 to the inoperative position of FIG. 6. The electromagnet 28 can be energized long enough to actuate the switch 29 in response to depression of a button (not shown) on the control panel of the machine which embodies the structure of FIG. 1. The switch 29 insures that the motor 20 cannot be started to move the section 62 from the position of FIG. 1 until and unless the locking mechanism of FIG. 4 disconnects the frame 19 from the frame 37.

The movement of the section 62 to its inoperative position further results in sidewise movement of the drum '7 above and away from the drum 8 so that the drum 7, 8 are then separated from each other by a gap 0 shown in FIG. 2 and being wide enough to afford satisfactory access to the drum 8.

The stub shafts 7a of the drum 7 are mounted in eccentric bores of the sleeves 30 which are rotatable in the frame 17 (see particularly FIG. 3). The center of curvature O of the arcuate path of the worm 16 is located on the common axis of the sleeves 30. The eccentricity e of the shafts 7a relative to the sleeves 30 is shown in FIG. 2. The sleeves 30 are rigid with the tensioning segments 36 for the chains 12 and are secured to the frame 19 by arcuate attaching means 31 so that the sleeves 30 rotate in the frame 17 when the section 62 moves relative to the section 61. It will be noted that the common axis of the sleeves 30 constitutes a pivot axis for the section 62. The eccentricity e is selected with a view to insure that the drums 7 and 8 are separated from each other by a gap :1 of requisite width as soon as the section 62 reaches the inoperative position of FIG. 6. It will be noted that such movement of the section 62 is accompanied by a movement of the drum 7 away from the drum 8, by automatic tensioning of the chains 12 and by automatic closing of the switch 24.

The guide means or ways 14 for the sheet gripping devices 13 include a group of outer rails I41 and a group of inner rails 142 normally defining with the rails 141 an endless path along which the gripping devices 13 advance seriatim from the sprocket wheels 11 toward and beyond the sprocket wheels 10, along the stamping roll 5, between the drums 7, 8, above the stack 9, and back to the sprocket wheels 11. When the section 62 is pivoted from the operative position of FIG. I, the path for the gripping devices 13 is interrupted due to movement of certain outer rails 141 relative to each other and due to simultaneous movement of certain inner rails 142 with respect to each other. As shown in FIG. 6, the leftmost fixed inner and outer rails have end faces 1424 and 1414 which are exposed in the inoperative position of the section 62. At the same time, the end faces 1422 of movable inner rails 142 on the frame 19 are moved away from the end faces 1421 of fixed inner rails 142 on the frame 17. Still further, the movable outer rails 145 on the frames 19 are displaced relative to fixed outer rails 146 on the frames 17. When the section 62 returns to the position of FIG. 1, the end faces 1414 and 1424 respectively abut against the end faces 1413, 1423 of rails on the movable frame 19, the end faces 1421 abut against the end faces 1422, and the rails 145 extend to the left of the rails 146. Each rail 145 is pivotally connected to an adjacent outer rail 141 on the frame 19, as at K, and each rail 145 carries at its right-hand end a coupling roller 32 which enters a coupling notch 33 of the associated rail 146 when the section 62 returns to the position of FIG. 2 (see also FIG. The means for securing the rails of the ways 14 to the frame 17 or 19 includes bolts, rivets or analogous fasteners. The inner rail 142 which is provided with the end face 1422 carries at its free end a coupling element 34 (see FIG. 7) which can engage the adjacent free end of the rail 142 having the end face 1421 when the frame 19 assumes the position of FIG. 5.

The frame 19 further carries outer rails having end faces 1412 which engage the end faces 1411 of outer rails on the frame 17 when the section 62 assumes its operative position.

The rails 145 of FIGS. 5 and 6 perform the following movements: In the positions of FIG. 5, the rails 145 are substantially aligned with the adjacent outer rails 14] on the frame 19 and are coupled thereto by pivot members K. The rollers 32 at the right-hand ends of the rails 145 extend into the notches 33 of the respective rails 146 on the frame 17. If the frame 19 is thereupon pivoted toward the position of FIG. 6, the rollers 32 are expelled from the respective notches 33 and ride along the respective rails 146. At the same time, each coupling member 34 becomes disengaged from the adjacent fixed inner rail 142 on the frame 17 and the end faces 1422 move downwardly and away from respective end faces 1421. Thus, the path for the sheet gripping devices 13 is interrupted or opened in the region of the end faces 1421. As shown in FIG. 7, the rails 142 which are normally connected to each other by coupling members 34 have end portions of reduced width. Each coupling member 34 preferably resembles a substantially U-shaped fork having prongs which flank the adjacent narrow end portions 142A of the fixed inner rails 142 on the frame 17 when the frame 19 assumes the position of FIG. 5. The purpose of the coupling members 34, rollers 32 and notches 33 is to insure accurate alignment between neighboring rails on the frames 17 and 19 in the operative position of the section 62. FIG. 6 shows that the length of the narrower portions 142A of the inner rails of FIG. 7 is sufficient to insure that such narrow portions can move relative to each other while the frame 19 moves between the positions of FIGS. 5 and 6.

When the section 62 moves back toward the operative position of FIG. 5, the movable inner and outer rails 142,141 move their end faces back into abutment with the end faces of adjacent inner and outer rails on the fixed frame 17. Also, the rollers 33 slide along the adjacent rails 146 due to gravity of the respective rails and reenter the respective notches 32. These rollers cooperate with the coupling elements 34 to insure accurate alignment of movable and fixed rails in the operative positions of the section 62. In addition, the rollers 33 in the notches 32 cooperate with the parts 23, 24 to prevent the section 62 from moving beyond the operative position.

The means for rotating the transfer conveyor 3 in synchronism with the rolls 4, 5 and drums 7, 8 is shown in the lower part of FIG. 1. A worm shaft 39 drives worms 40, 43 which respectively mesh with worm wheels 41, 45. The worm wheel 41 drives a gear 42 for the conveyor 3 and rolls 4, 5, and the worm wheel 45 drives a gear 44 for the drums 7, 8. The gear 44 indirectly drives a gear 58 (FIG. 3) on one of the stub shafts 7a for the drum 7.

The manner in which the gripping devices 13 are actuated to engage the leading edges of sheets I in the region of the rolls 4, 5 and to release the remnants l" of sheets 1 at a level above the storing platform 9a is known from the art and is not specifically shown in the drawing.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. In a machine for manipulating imprinted sheets, particularly in a machine for providing imprinted sheets with cutouts and for separating the cutouts from the remnants of the respective sheets, a combination comprising a plurality of sheet treating members including a rotary sheet treating member; a sheet transporting unit including at least one endless flexible element, having a stationary portion and a longitudinally spaced movable portion which is pivotal relative to said stationary portion, and said sheet treating member being located where said movable portion pivots relative to the sheet treating member, sheet gripping devices connected with said flexible element, and guide means for said gripping devices, said guide means comprising fixed first portions and movable second portions; and drive means actuatable to move a portion of said flexible element and said second portions of said guide means about a pivot axis which is at least closely adjacent to the axis of said rotary sheet treating member between an operative position in which said first and second portions of said guide means define for said gripping devices an endless path and an inoperative position in which said path is interrupted.

2. A combination as defined in claim 1, wherein said sheet treating members include a second sheet treating member adjacent to said rotary sheet treating member, said endless path extending between said rotary sheet treating member and said second sheet treating member.

3. A combination as defined in claim I, further comprising means for moving said flexible element in a predetermined direction and sheet storing means disposed downstream of said sheet treating members, as considered in said predetermined direction, and arranged to receive sheets from successive gripping devices.

4. A combination as defined in claim 1, further comprising a fixed first frame for said first portions of said guide means, a second frame for said second portions of said guide means, said second frame being movable by said drive means, and bearing sleeve means secured to said second frame and eccentrically supporting said rotary sheet treating member, said pivot axis coinciding with the axis of said sleeve means so that said rotary sheet treating member moves sideways when said drive means moves said second frame to thereby rotate said bearing sleeve means.

5. A combination as defined in claim 1, further comprising a first frame for said first portions of said guide means and a second frame for said second portions of said guide means, said second frame being movable by said drive means and said drive means including a worm drive having mating first and second portions respectively mounted on said first frame and said second frame and prime mover means for moving one of said first and second portions of said worm drive relative to the other of said portions and relative to the respective frame.

6. A combination as defined in claim 5, wherein said first portion of said worm drive is a worm wheel which is rigid with said first frame and said second portion of said worm drive is a worm which is rotatable on said second frame by said prime mover means.

7. A combination as defined in claim 6, wherein said drive means further comprises a casing for said worm, said worm being movable axially in said casing and said drive means further comprising means for biasing said worm axially against said casing.

8. A combination as defined in claim 1, wherein said first and second portions of said guide means comprise coupling elements which are respectively engaged with and disengaged from each other in the operative and inoperative positions of said second portions.

9. A combination as defined in claim 8, wherein said coupling elements include a notch in one of said first portions and a roller provided on one of said second portions and being received in said notch in said opera- 12 tive position of said second portions of said guide means.

10. A combination as defined in claim 1, further comprising means for moving said flexible element in a predetermined direction and means for arresting said flexible element in a position in which said gripping devices are spaced apart from said rotary sheet treating member.

11. A combination as defined in claim 10, wherein said means for moving said flexible element comprises a disengageable clutch.

12. A combination as defined in claim l,.further comprising a frame for said second portions of said guide means, said frame being movable by said drive means and further comprising tensioning means provided on said frame and arranged to tension said fle xible element in response to movement of said second portions of said guide means to said inoperative position.

13. A combination as defined in claim 12, wherein said tensioning means comprises a roller and a segmentshaped tensioning member.

14. A combination as defined in claim 1, further comprising a fixed frame and a second frame supporting said second portions of said guide means, said second frame being movable by said drive means and further comprising means for releasably locking said second frame to said first frame in one of said positions of said second portion of said guide means.

15. A combination as defined in claim 14, wherein said one position is said operative position of said second portions of said guide means and said means for locking comprises a projection on said second frame and a locking element provided on said first frame and movable into and from engagement with said projection in said operative positions of said second portions of said guide means.

16. A combination as defined in claim 15, wherein said means for locking further comprises means for biasing said locking element into engagement with said projection.

17. A combination as defined in claim 14, wherein said one position is said operative position of said second portions of said guide means and said means for locking comprises a first locking element provided on said second frame, a second locking element mounted on said first frame. means for moving one of said locking elements into and from engagement with the other locking element, and means for actuating said drive means in response to disengagement of said one locking element from said other locking element.

18. A combination as defined in claim 17, wherein said drive means comprises an electric motor and said means for actuating comprises electric switch means which is arranged to start said motor in response to disengagement of said one locking element from said other locking element.

19. A combination as defined in claim 17, wherein said means for moving said one locking element relative to said other locking element comprises an electromagnet. 

1. In a machine for manipulating imprinted sheets, particularly in a machine for providing imprinted sheets with cutouts and for separating the cutouts from the remnants of the respective sheets, a combination comprising a plurality of sheet treating members including a rotary sheet treating member; a sheet transporting unit including at least one endless flexible element, having a stationary portion and a longitudinally spaced movable portion which is pivotal relative to said stationary portion, and said sheet treating member being located where said movable portion pivots relative to the sheet treating member, sheet gripping devices connected with said flexible element, and guide means for said gripping devices, said guide means comprising fixed first portions and movable second portions; and drive means actuatable to move a portion of said flexible element and said second portions of said guide means about a pivot axis which is at least closely adjacent to the axis of said rotary sheet treating member between an operative position in which said first and second portions of said guide means define for said gripping devices an endless path and an inoperative position in which said path is interrupted.
 2. A combination as defined in claim 1, wherein said sheet treating members include a second sheet treating member adjacent to said rotary sheet treating member, said endless path extending between said rotary sheet treating member and said second sheet treating member.
 3. A combination as defined in claim 1, further comprising means for moving said flexible element in a predetermined direction and sheet storing means disposed downstream of said sheet treating members, as considered in said predetermined direction, and arranged to receive sheets from successive gripping devices.
 4. A combination as defined in claim 1, further comprising a fixed first frame for said first portions of said guide means, a second frame for said second portions of said guide means, said second frame being movable by said drive means, and bearing sleeve means secured to said second frame and eccentrically supporting said rotary sheet treating member, said pivot axis coinciding with the axis of said sleeve means so that said rotary sheet treating member moves sideways when said drive means moves said second frame to thereby rotate said bearing sleeve means.
 5. A combination as defined in claim 1, further comprising a first frame for said first portions of said guide means and a second frame for said second portions of said guide means, said second frame being movable by said drive means and said drive means including a worm drive having mating first and second portions respectively mounted on said first frame and said second frame and prime mover means for moving one of said first and second portions of said worm drive relative to the other of said portions and relative to the respective frame.
 6. A combination as defined in claim 5, wherein said first portion of said worm drive is a worm wheel which is rigid with said first frame and said second portion of said worm drive is a worm which is rotatable on said second frame by said prime mover means.
 7. A combination as defined in claim 6, wherein said drive means further comprises a casing for said worm, said worm being movable axially in said casing and said drive means further comprising means for biasing said worm axially against said casing.
 8. A combination as defined in claim 1, wherein said first and second pOrtions of said guide means comprise coupling elements which are respectively engaged with and disengaged from each other in the operative and inoperative positions of said second portions.
 9. A combination as defined in claim 8, wherein said coupling elements include a notch in one of said first portions and a roller provided on one of said second portions and being received in said notch in said operative position of said second portions of said guide means.
 10. A combination as defined in claim 1, further comprising means for moving said flexible element in a predetermined direction and means for arresting said flexible element in a position in which said gripping devices are spaced apart from said rotary sheet treating member.
 11. A combination as defined in claim 10, wherein said means for moving said flexible element comprises a disengageable clutch.
 12. A combination as defined in claim 1, further comprising a frame for said second portions of said guide means, said frame being movable by said drive means and further comprising tensioning means provided on said frame and arranged to tension said flexible element in response to movement of said second portions of said guide means to said inoperative position.
 13. A combination as defined in claim 12, wherein said tensioning means comprises a roller and a segmentshaped tensioning member.
 14. A combination as defined in claim 1, further comprising a fixed frame and a second frame supporting said second portions of said guide means, said second frame being movable by said drive means and further comprising means for releasably locking said second frame to said first frame in one of said positions of said second portion of said guide means.
 15. A combination as defined in claim 14, wherein said one position is said operative position of said second portions of said guide means and said means for locking comprises a projection on said second frame and a locking element provided on said first frame and movable into and from engagement with said projection in said operative positions of said second portions of said guide means.
 16. A combination as defined in claim 15, wherein said means for locking further comprises means for biasing said locking element into engagement with said projection.
 17. A combination as defined in claim 14, wherein said one position is said operative position of said second portions of said guide means and said means for locking comprises a first locking element provided on said second frame, a second locking element mounted on said first frame, means for moving one of said locking elements into and from engagement with the other locking element, and means for actuating said drive means in response to disengagement of said one locking element from said other locking element.
 18. A combination as defined in claim 17, wherein said drive means comprises an electric motor and said means for actuating comprises electric switch means which is arranged to start said motor in response to disengagement of said one locking element from said other locking element.
 19. A combination as defined in claim 17, wherein said means for moving said one locking element relative to said other locking element comprises an electromagnet. 